What Australian Medical, Allied Health and Educational Experts Want from an Autism Spectrum Disorder Diagnostic Process

Background: In the absence of empirical evidence regarding the accuracy of various autism spectrum disorder (ASD) diagnostic practices, numerous clinical guidelines on the topic rely on expert consensus. However, the process for attaining this consensus is not often articulated.

Objectives: This Delphi survey sought to generate consensus recommendations regarding assessment and diagnosis from medical, allied health and educational experts in Australia.

Methods: Steering committee members from medical, allied health, education and ASD specific backgrounds were invited to nominate up to 20 experts in the ASD assessment field. This resulted in 118 professionals being invited to participate, with a total of 77 participants from a wide variety of disciplines completing (n = 66) or partially completing (n = 11) the first round of the Delphi survey. The majority of participants were diagnosticians (n=48), with other participants reporting their involvement in other aspects of the clinical or educational management of autistic children or adults. Participants had been involved in the assessment process for ASD for a median of 15 years (range = <1–40 years). Participants practiced within public and private settings, including community, hospital and university environments. The participants worked with individuals on the autism spectrum with a wide age range, from babies to older adults. A total of 42 participants provided responses on the Round 2 survey.

The questions contained within Round 1 of the Delphi Survey were developed on the basis of a scoping review. A range of potential assessment components were provided with a five point scale to allow participants to indicate their agreement regarding if each component should be part of an ASD assessment. Participants were provided with an opportunity to make comments after each question, each section and at the end of the survey. The questions contained within Round 2 of the Delphi Survey were developed on the basis of Round 1 quantitative and qualitative results, with a focus on items where agreement had not been achieved.

Two methods were utilised to determine if consensus had been achieved for a recommendation, based on the median / interquartile range and proportion of agreement. Agreement was considered to exist if both criteria were met and partial agreement was achieved if only one of the two criteria was met.

Results: Agreement was obtained for many recommendations regarding who, where and how an ASD assessment should be conducted. The strongest agreement was obtained for recommendations addressing the prerequisite knowledge and experience of professionals conducting ASD assessments, topics to be addressed during an ASD assessment (in particular history and symptoms), and assessment approaches (observation and interview).

Conclusions: Results of the Delphi survey provide clear support for guideline recommendations that are considered acceptable by medical, allied health and educational professionals.